1. Field of the Invention
The present invent relates to an ink jet recording head of an ink jet recording apparatus that performs recording by discharging inks.
2. Description of the Related Art
FIG. 17 shows an exploded perspective view for explaining a construction of a conventional ink jet recording head. FIG. 18 shows a cross sectional view of a recording head cartridge in which an ink tank is installed in the ink jet recording head. FIGS. 19A through 19C show schematic sectional enlarged views for explaining a step of forming an ink flow path.
An ink jet recording head 1020 shown in FIGS. 17 and 18 has hitherto used a method of assembling a tank holder unit 1200 by ultrasonic-wave-welding an flow path forming member 1220 to a tank holder 1210 in order to form an ink flow path 1214 for guiding an ink in an ink tank 1040 to a recording element unit 1300 via the tank holder 1201.
As shown in FIG. 18, in a state where the ink tank 1040 is installed in the ink jet recording head 1020, the ink is supplied into the ink jet recording head 1020 via a joint portion including a filter 1230 and a seal rubber 1240 from an ink supply port 1401 of the ink tank 1040. The ink is supplied to a recording element substrate 1330 of the recording element unit 1300 via the ink flow path 1214, and is then discharged onto a recording sheet (unillustrated) by dint of energy generated by energy elements (unillustrated) within a silicon substrate.
At this time, the ink flow path 1224 is formed by connecting the flow path forming member 1220 to the tank holder 1210 by the ultrasonic wave welding. To explain an assembling step with reference to FIGS. 19A through 19C, the tank holder 1210 is, as shown in FIG. 19A, formed with a groove serving as a burr reservoir 1218 in a connecting portion, while the flow path forming member 1220 is formed with a welding rib 1227 on the connecting portion. As shown in FIG. 19B, the flow path forming member 1220 is placed on the tank holder so that the welding rib 1227 is fitted into the groove of the burr reservoir 1218. Further, the flow path forming member 1220 is pressed from above by an ultrasonic wave welding horn 1054, and ultrasonic waves are oscillated while applying a pressure. With the oscillations, as shown in FIG. 19C, the welding rib 1227 spreads in the burr reservoir 1218 while being melted, and the tank holder 1210 and the flow path forming member 1220 are thus firmly connected together, thereby forming the ink flow path 1224.
Note that the numeral 1310 represents a first plate, 1311 designates an ink supply port formed in the first plate, 1320 denotes a second plate, 1330 stands for a recording element substrate, 1337 represents a discharge port formed in the recording element substrate, 1340 indicates an electric wiring board, and 1341 designates an external signal input terminal for electrically connecting the ink jet recording head to the ink jet recording apparatus in FIGS. 17 and 18. The first plate 1311 is connected to the flow path forming member 1220 and supports the recording element substrate 1330 and the second plate 1320 as well. The second plate 1320 supports the electric wiring board 1340. These members constitute the recording element unit 1300.